Feltville Formation (NJJf;5)

Feltville Formation (Olsen, 1980) - Interbedded brownish-red to light-grayish-red, fine- to coarse-grained sandstone, gray and black, coarse siltstone in upward-fining cycles, and silty mudstone. Fine-grained sandstone and siltstone are moderately well sorted, commonly cross-laminated, and have 15 percent or more feldspar; interbedded with brownish-red, indistinctly laminated, bioturbated calcareous mudstone. Thermally metamorphosed into hornfels where in contact with Preakness Basalt. Near the base are two thin, laterally continuous beds of black, carbonaceous limestone and gray, calcareous siltstone, each up to 3 m (10 ft) thick. These contain abundant fish, reptile, anthropod, and diagnostic plant fossils. Three or four, thin, gray to black siltstone and mudstone sequences occur in upper part of unit. Near Oakland, subrounded pebbles to cobbles of quartzite and quartz in a red siltstone and sandstone matrix (Jfc) interfinger with sandstone and siltstone of the Feltville Formation. Maximum thickness about 155 m (510 ft).

State	New Jersey
Name	Feltville Formation
Geologic age	Lower Jurassic
Original map label	Jf
Comments	Newark Supergroup, Brunswick Group (Lyttle and Epstein, 1987). Units Jf and Jfc are described together on printed map. The units were split into separate records and appropriate descriptions for each were used.
Primary rock type	siltstone
Secondary rock type	sandstone
Other rock types	fine-grained mixed clastic; mudstone; limestone
Lithologic constituents	Major Sedimentary > Clastic > Siltstone (Bed)coarse siltstone; fine-grained sandstone and siltstone are moderately well sorted, commonly cross-laminated, and have 15 percent or more feldspar. Near the base are two thin, laterally continuous beds of black, carbonaceous limestone and gray, calcareous siltstone, each up to 3 m (10 ft) thick. These contain abundant fish, reptile, anthropod, and diagnostic plant fossils. Three or four, thin, gray to black siltstone and mudstone sequences occur in upper part of unit. Sedimentary > Clastic > Sandstone (Bed)Interbedded brownish-red to light-grayish-red, fine- to coarse-grained sandstone. Fine-grained sandstone and siltstone are moderately well sorted, commonly cross-laminated, and have 15 percent or more feldspar. Minor Sedimentary > Clastic > Mudstone (Bed)silty mudstone; interbedded with brownish-red, indistinctly laminated, bioturbated calcareous mudstone; three or four, thin, gray to black siltstone and mudstone sequences occur in upper part of unit. Sedimentary > Clastic > Mixed-clastic > Siltstone-mudstone (Bed)silty mudstone; interbedded with brownish-red, indistinctly laminated, bioturbated calcareous mudstone; three or four, thin, gray to black siltstone and mudstone sequences occur in upper part of unit. Incidental Sedimentary > Carbonate > Limestone (Bed)Near the base are two thin, laterally continuous beds of black, carbonaceous limestone and gray, calcareous siltstone, each up to 3 m (10 ft) thick. These contain abundant fish, reptile, anthropod, and diagnostic plant fossils.
Map references	Dalton, R. F., Herman, G. C., Monteverde, D. H., Pristas, R. S., Sugarman, P. J., Volkert, R. A., 1999, New Jersey Department Of Environmental Protection, Bedrock Geology and Topographic Base Maps of New Jersey: New Jersey Geological Survey CD Series CD 00-1; ARC/INFO (v. 7.1) export file: geology.e00, scale 1:100,000, unit description files: cslegend.pdf and nlegend.pdf, metadata: metast.pdf.
Unit references	Dalton, R. F., Herman, G. C., Monteverde, D. H., Pristas, R. S., Sugarman, P. J., Volkert, R. A., 1999, New Jersey Department Of Environmental Protection, Bedrock Geology and Topographic Base Maps of New Jersey: New Jersey Geological Survey CD Series CD 00-1; ARC/INFO (v. 7.1) export file: geology.e00, scale 1:100,000, unit description files: cslegend.pdf and nlegend.pdf, metadata: metast.pdf. Drake, Avery A. Jr.,Volkert, Richard, A., Monteverde, Donald H., Herman, Gregory C., Houghton,Hugh F., Parker, Ronald A., and Dalton, Richard F., 1996, Bedrock Geologic Map of Northern New Jersey: U.S. Geological Survey Miscellanenous Investigations Map I-2540-A, scale 1 to 100,000, 4 cross sections, 2 sheets, size 56x40; 58x41. [http://pubs.er.usgs.gov/publication/i2540A] Olsen, P.E., 1980, The latest Triassic and Early Jurassic formations of the Newark basin (eastern North America, Newark Supergroup); stratigraphy, structure, and correlation: New Jersey Academy of Science Bulletin, v. 25, no. 2, p. 25-51. Lyttle, P.T., and Epstein, J.B., 1987, Geologic map of the Newark 1 x 2 degree quadrangle, New Jersey, Pennsylvania, and New York: U.S. Geological Survey Miscellaneous Investigations Series Map I-1715, scale 1:250,00. [http://pubs.er.usgs.gov/publication/i1715]